Icons disappearing from cmd+tab application switcher

@mankoff got me on the right path. Here's what I had to do in order to get what I want:

1. Copy Terminal.app to a new file (ex: MyTerminal.app)
2. Change the icon of the app by:
   1. Copy an icon image to the clipboard from Preview
   2. Right-click (Command-click) on the app
   3. Select "Get Info"
   4. Click the app icon in the upper left corner
   5. Pasting the new icon image from the clipboard
3. Right-click on the App and choose "Show Package Contents"
4. Change the following values in Contents/Info.plist:
   1. "Bundle display name" -> "MyTerminal"
   2. "Bundle identifier" -> a unique app-specific string. I chose "ca.softcraft.myterminal" as I own the domain "softcraft.ca"
   3. Bundle name -> "MyTerminal"
   4. Document Types -> Delete
   5. URL Types -> Delete
   6. Application has localized display name -> uncheck
   7. Exported Type UTIs -> Delete
5. I deleted a bunch of the localization settings (Contents/Resources/*.lproj) as they're not necessary for me; I just need English
6. In Contents/Resources/English/InfoPlist.strings, I deleted the "CFBundleName" and "CFBundleDisplayName" override settings
7. In Contents/Resources/Initial Settings, I deleted all but one of the *.terminal files.
   1. I'm using a custom terminal setting, but there's no reason you couldn't use Basic
   2. In Contents/Resources/Initial Settings/settings.plist, I made sure my "Default Settings" value was set to the name of my .terminal file
8. I set the values in the .terminal file to match what I wanted on open
   1. This is just a .plist file with a different extension; you can use Property List Editor to modify it
   2. You can also set these using Terminal itself and then export them
   3. I mainly changed "CommandString" to be what I want launched when I run the new "app".

This works excellently. The new "Terminal" apps are independent of each other and of the main Terminal. I can spin off new ones fairly quickly now.

I also did this with Firefox to create a site-specific browser for my development website. (I had tried Mozilla Prism but found it too limiting).

I'm having the same issue as Arnold. The problem might even be slighty worse for me; opun freezing, I can only use keyboard input; mouse clicks aren't registered anymore. I use QuickSilver to launch a terminal and running "killall -9 Dock" two times kills the dock and releases the mouse. After a couple of minutes the dock is relaunched. Also sending the HUP or INT to Dock will kill it. Sending the TERM signal doesn't though.

I found that the problem can be circumvented by rebooting the system and after reboot ensuring that the first thing you do is to open the notification center. I think that by sleeping your mac without having the notification center open before that is what makes it crash.

Sadly, I didn't find any way to check what's keeping the Dock process busy. It doesn't seem to be the notification centre itself that's crashing (it keeps responding to mouse clicks while nothing else does) but the Dock. So far the only thing I came up with is that this is a problem with launchd, but that doesn't help a lot because killing launchd will kill every application you have running.